Patch

ABSTRACT

The patch of the present invention comprises a backing layer and an adhesive layer laminated on the backing layer, wherein a water vapor transmission rate of the backing layer is 400 g/m 2 ·24 hours or more, and the adhesive layer comprises a drug, dimethylsulfoxide and an adhesive. Such a patch does not fall off easily even after long wear.

TECHNICAL FIELD

The present invention relates to a patch.

BACKGROUND ART

Dimethyl sulfoxide (DMSO) is used in a formulation to dissolve a drug therein. For example, Patent Literature 1 discloses a patch of diclofenac sodium having DMSO used as a solubilizing agent.

CITATION LIST Patent Literature

-   Patent Literature 1: International Publication No. WO 2013/191128

SUMMARY OF INVENTION Technical Problem

The adhesiveness of the patch generally decreases gradually with time. The present inventors have found that when DMSO is blended in an adhesive layer of a patch, a composition which gives tackiness to the patch is plasticized, resulting in a decrease in tackiness of the adhesive layer. The present inventors have also found that when the patch comprising DMSO is worn for a long time (such as 24 hours), sufficient adhesiveness may not last till the end and so the patch may fall off before treatment is completed.

Solution to Problem

The present inventors have found that by combining an adhesive layer comprising DMSO with a backing having a particular water vapor transmission rate, the adhesiveness of a patch after long wear is greatly improved, and thus have completed the present invention.

A patch of the present invention comprises: a backing layer and an adhesive layer laminated on the backing layer, wherein a water vapor transmission rate of the backing layer is 400 g/m²·24 hours or more, and the adhesive layer comprises a drug, DMSO and an adhesive.

The water vapor transmission rate of the backing layer may be 750 g/m²·24 hours or more, or may be 2000 g/m²·24 hours or more.

The adhesive layer may comprise at least one adhesive selected from a rubber adhesive, an acrylic adhesive and a silicone adhesive, and may comprise a styrene-isoprene-styrene block copolymer.

The drug may be one or more drugs selected from the group consisting of ketoprofen, diclofenac sodium and indomethacin. In addition, the adhesive layer may comprise an organic acid.

Advantageous Effects of Invention

According to the patch of the present invention, by using a backing layer having a high water vapor transmission rate, sufficient adhesiveness is maintained for a long time. Thus, the patch does not fall off easily even after long wear (such as 24 hours). As a result, when the drug is a drug with analgesic and anti-inflammatory effects such as ketoprofen, diclofenac sodium or indomethacin, a sufficient cumulative skin permeation amount of the drug can be achieved more surely after the patch is worn on the skin of a patient for 24 hours. In addition, the maximum plasma concentration (Cmax) of the drug is achieved more surely. Therefore, according to the patch of the present invention, more effective drug treatment is possible.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing the relationship between the water vapor transmission rate of the backing layer and the rate of decrease in the concentration in % by mass of DMSO (hereinafter referred to “DMSO concentration”) based on the total mass of the adhesive layer (Test Example 1).

FIG. 2 is a graph showing the relationship between the water vapor transmission rate of the backing layer and the half-life of the concentration in % by mass of DMSO based on the total mass of the adhesive layer (Test Example 1).

DESCRIPTION OF EMBODIMENTS

A patch of the present invention comprises a backing layer and an adhesive layer laminated on the backing layer. The adhesive layer is usually laminated on one side of the backing layer, and a peelable film is laminated on the other side of the adhesive layer as needed.

First, the adhesive layer will be described. The adhesive layer is a part that sticks to the skin when the patch is worn, and comprises at least a drug, DMSO and an adhesive.

The drug is a component soluble in DMSO. The drug may be a drug with analgesic and anti-inflammatory effects such as loxoprofen, felbinac, flurbiprofen, indomethacin, ketoprofen and diclofenac sodium, or may be an analgesic drug or narcotic drug such as buprenorphine, fentanyl and butorphanol, or other drugs such as clonidine, estradiol, tulobuterol or oxybutynin. The content of the drug is, for example, 1% by mass to 20% by mass or 2% by mass to 10% by mass based on the total mass of the adhesive layer.

DMSO dissolves the drug to improve the skin permeability of the drug, while it leads to a decrease in tackiness of the adhesive layer. From the viewpoint of balancing these, the content of DMSO is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, further preferably 2% by mass to 10% by mass, and particularly preferably 3% by mass to 10% by mass, based on the total mass of the adhesive layer.

The ratio of the drug to DMSO varies depending on drugs, and for example, when diclofenac sodium is contained as a drug, from the viewpoint of improving the skin permeability of diclofenac sodium and preventing diclofenac sodium from crystallizing, the ratio of the mass of diclofenac sodium to the mass of DMSO in the adhesive layer in the patch just before application is preferably 1:0.3 to 1:4, more preferably 1:0.4 to 1:3, further preferably 1:0.6 to 1:3, and particularly preferably 1:0.72 to 1:3.

The adhesive layer may comprise at least one adhesive selected from a rubber adhesive, an acrylic adhesive and a silicone adhesive. The rubber adhesive is, for example, polyisoprene, polyisobutylene (PIB), polybutadiene, a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene (SIS) block copolymer, a styrene-butadiene rubber, a styrene-isoprene rubber, or a combination thereof. From the viewpoint of enhancing the skin permeability of the drug and enhancing the tackiness of the patch, among them, an SIS block copolymer, PIB or a combination thereof is preferable, and a mixture of an SIS block copolymer and PIB is more preferable. The acrylic adhesive is, for example, an adhesive obtained by polymerizing or copolymerizing at least one (meth)acrylic monomer such as (meth)acrylic acid, 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate or hydroxyethyl (meth)acrylate. The silicone adhesive comprises, as a main component, for example, a silicone rubber such as polydimethylsiloxane, polymethylvinylsiloxane or polymethylphenylsiloxane.

When the adhesive is a rubber adhesive, from the viewpoint of tackiness of the patch, the content of the adhesive may be 10% by mass to 70% by mass, 10% by mass to 40% by mass, 15% by mass to 50% by mass, 15% by mass to 35% by mass, or 30% by mass to 40% by mass, based on the total mass of the adhesive layer. When the adhesive is an acrylic adhesive or silicone adhesive, the content of the adhesive may be 50% by mass to 90% by mass, based on the total mass of the adhesive layer.

The adhesive layer may further comprise an organic acid for the purpose of promoting the transdermal absorption of the drug, preventing the drug from crystallizing with time, or the like. Examples of the organic acid include aliphatic acids such as aliphatic monocarboxylic acids (such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, nonanoic acid, capric acid, lauric acid, oleic acid, linoleic acid, linolenic acid, isostearic acid, sorbic acid and pyruvic acid), aliphatic dicarboxylic acids (such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid and oxaloacetic acid), and aliphatic tricarboxylic acids (such as aconitic acid and propane tricarboxylic acid); hydroxy acids (such as glycolic acid, lactic acid, tartronic acid, glyceric acid, hydroxybutyric acid, malic acid, tartaric acid, citric acid, isocitric acid, sugar acid, gluconic acid, glucuronic acid, ascorbic acid and erythorbic acid); aromatic carboxylic acids (such as benzoic acid, gallic acid, salicylic acid, acetylsalicylic acid and phthalic acid); other organic acids (such as mesylic acid and besylic acid); or salts thereof (for example, a alkali metal salt such as a sodium salt). When the drug is diclofenac sodium, from the viewpoint of promoting the transdermal absorption of diclofenac sodium and preventing diclofenac sodium from crystallizing out with time, among these organic acids, citric acid, oleic acid, mesylic acid or an alkali metal salt thereof is particularly preferable. By comprising such an organic acid, a sufficient cumulative skin permeation amount of the drug is obtained more surely. These organic acids may be used alone or in combination of two or more thereof. From the viewpoint of improving the skin permeability of the drug and preventing the drug from crystallizing over time, the content of the organic acid may be 0.01% by mass to 20% by mass %, 0.1% by mass to 15% by mass, or 0.2% by mass to 13% by mass, based on the total mass of the adhesive layer.

The adhesive layer may further comprise a tackifier, a plasticizer or other additives. The tackifier is, for example, an alicyclic saturated hydrocarbon resin, a hydrogenated rosin ester, a terpene resin or a combination thereof. The content of the tackifier is, for example, 5% by mass to 60% by mass, 10% by mass to 50% by mass, 25% by mass to 45% by mass, or 30% by mass to 35% by mass %, based on the total mass of the adhesive layer. The plasticizer is, for example, a liquid paraffin or a liquid polybutene. The content of the plasticizer is, for example, 7% by mass to 70% by mass, 10% by mass to 60% by mass or 11% by mass to 25% by mass, based on the total mass of the adhesive layer.

The adhesive layer may be a single layer consisting of one composition, or may be a multilayer in which layers having different compositions are laminated. From the viewpoint of properly adhering the patch to the skin, the total thickness of the adhesive layer is preferably 10 μm to 1000 μm and more preferably 30 μm to 300 μm.

The probe tack value of the adhesive layer is preferably 30 gF or more, and more preferably 40 gF or more. The probe tack value of the adhesive layer may be, for example, 43 gF or more, 44 gF or more, 53 gF or more, 61 gF or more, 68 gF or more, or 71 gF or more. The higher the probe tack value is, the more the adhesiveness of the patch is improved. From the viewpoint of reducing skin irritation, the probe tack value may be 2000 gF or less, 1500 gF or less, or 1000 gF or less. In the present specification, the probe tack value of the adhesive layer is measured in accordance with the probe tack test method of ASTM D2979.

Next, the backing layer will be described. The backing layer holds the adhesive layer. The water vapor transmission rate of the backing layer is 400 g/m²·24 hours or more. When the backing layer having such a high water vapor transmission rate is used, DMSO gradually volatilizes from the patch worn on the skin, so that the tackiness of the patch improves and the patch does not fall off easily even after long wear. Although the water vapor transmission rate is originally an indicator for the transmission of water, the present inventors have found that the backing having a high water vapor transmission rate also has a high transmission (volatility) of DMSO. The water vapor transmission rate of the backing layer may be, for example, 422 g/m²·24 hours or more, 750 g/m²·24 hours or more, 2000 g/m²·24 hours or more, 2077 g/m²·24 hours or more, 4000 g/m²·24 hours or more, 5500 g/m²·24 hours or more, 5667 g/m²·24 hours or more, or 8408 g/m²·24 hours or more. The upper limit of the water vapor transmission rate may be 20000 g/m²·24 hours. The water vapor transmission rate of the backing layer in such a range is more effective for improving the tackiness of the patch since DMSO volatilizes from the adhesive layer more easily.

The water vapor transmission rate of the backing layer in the present invention refers to the water vapor transmission rate at 40° C. as defined in JIS Z0208: 1976 (water vapor transmission rate test method (cup method) of moisture-proof packaging material).

It is preferable that the backing layer is a monolayer or a laminate of a fabric (a woven fabric, a nonwoven fabric or knitted fabric) made of fibers, or a nonporous or porous film (sheet). A material of the backing layer is preferably one or more materials selected from polyester (such as polyethylene terephthalate (PET), polyethylene isophthalate, polypropylene terephthalate, polypropylene isophthalate, polybutylene terephthalate or polyethylene naphthalate), polyolefin (a polymer or copolymer of a vinyl monomer such as ethylene, propylene, vinyl acetate or acrylonitrile), polyamide (such as nylon or silk), polyurethane (PU), or cellulose (such as cotton or hemp). The fabric (a woven fabric, a nonwoven fabric or knitted fabric) may be coated with a rubber composition. The rubber composition comprises a rubber adhesive. The rubber adhesive is, for example, polyisoprene, PIB, polybutadiene, a styrene-butadiene-styrene block copolymer, an SIS block copolymer, a styrene-butadiene rubber, a styrene-isoprene rubber, or a combination thereof. The rubber composition may comprise a tackifier. The tackifier is, for example, an alicyclic saturated hydrocarbon resin, a hydrogenated rosin ester, a terpene resin, or a combination thereof. The rubber compositions may further comprise an additive such as a plasticizer or a filler. The thickness of the backing layer is, for example, 0.1 mm to 2 mm. The basis weight of the backing layer is, for example, 30 g/m² to 200 g/m². In the present specification, the thickness and basis weight of the backing layer are measured in accordance with JIS L 1906: 2000.

When the backing layer is a fabric, it is preferable that the 50% modulus (JIS L 1018: 1999) in both the longitudinal direction (direction of material flow) and the transverse direction (width direction of material) of the backing layer is 1 N/50 mm to 12 N/50 mm. When the 50% modulus is 12 N/50 mm or less, the stress applied to the patch due to stretching of the skin is lower, and the adhesiveness to the skin thus is better.

When the backing layer is a film, the material is preferably a material having a high water vapor transmission (high DMSO transmission) such as polyurethane. The film made of polyurethane is excellent in stretchability and therefore preferable from the viewpoint of enhancing adhesiveness and conformability of the patch to the skin.

It is preferable that the backing layer is, for example, a nonwoven fabric or film made of polyurethane, a knit fabric made of polyethylene terephthalate, a polyester fabric coated with a rubber composition, or a combination thereof. More specifically, it is preferable that the backing layer is a laminate of a film made of polyurethane and a nonwoven fabric made of polyurethane fibers, a nonwoven fabric made of PET fibers, or a polyester fabric coated with a rubber composition.

From the viewpoint of preventing the drug from crystallizing in a unused patch, the DMSO concentration in the patch just before application may be, for example, 1% by mass to 20% by mass, 2% by mass to 12% by mass, 2% by mass to 10% by mass, or 2% by mass to 8% by mass, based on the total mass of the adhesive layer. In addition, DMSO concentration in the patch after 24 hours of wear is preferably 0.1% by mass to 4% by mass, and more preferably 0.1% by mass to 1.5% by mass. It is preferable that the backing layer is one capable of achieving such a decrease in the DMSO concentration. More specifically, when the DMSO concentration in the patch just before application is 2% by mass to 8% by mass, a backing layer in which the decrease rate of the DMSO concentration is 0.08% by mass/hour to 0.16% by mass/hour (that is, a decrease of 1.92% by mass to 3.84% by mass per 24 hours) is preferable. From another viewpoint, when the DMSO concentration in the patch just before application is 2% by mass to 8% by mass, the backing layer in which the half-life of the DMSO concentration is 5 hours to 24 hours is preferable. A backing layer satisfying such a condition tends to maintain sufficient adhesiveness even after worn for 24 hours. Both the decrease rate and the half-life of the DMSO concentration in the patch as described are calculated by placing the patch with the backing layer facing upward under the conditions of 30° C. and 65% RH and measuring the change in the DMSO concentration in the patch by gas chromatography (GC).

The patch may be prepared, for example, by the following method without being limited thereto, and may be prepared by using any known method. First, components constituting an adhesive layer are mixed with each other at a predetermined ratio to obtain a mixture having the components homogeneously dissolved therein. Next, the mixture is spread on a peelable film (release film or release liner) at a predetermined thickness to form an adhesive layer. Then, a backing layer is contact bonded to the adhesive layer with the adhesive layer sandwiched between the release liner and the backing layer. Finally, it may be cut into a desired shape to obtain the patch. In this case, the release liner is removed at the time of applying the patch.

EXAMPLES

(Preparation of Patch)

In the following examples, unless otherwise stated, a patch was prepared as follows:

1) Components of an adhesive layer were mixed with each other and spread on a release film (PET film which had been subjected to release treatment). This was dried to remove DMSO to a predetermined amount and form the adhesive layer (100 g/m²) having a thickness of 100 μm.

2) A backing layer was laminated on the adhesive layer to obtain a patch. The patch was cut into pieces having a suitable size as appropriate.

(Measurement of Water Vapor Transmission Rate of Backing Layer)

In the following examples, the water vapor transmission rate of the backing layer used was measured under the conditions of 40° C. and 90% RH in accordance with JIS Z0208.

(Evaluation of Tackiness of Patch)

In the following examples, unless otherwise stated, the tackiness of a patch was evaluated by the 180° peel test described below:

1) A test piece of 1 cm×5 cm was prepared from the patch and stored under predetermined conditions for a predetermined time.

2) A release film was removed from the test piece, and the test piece was applied on a stainless steel plate.

3) Using an Instron type tensile tester, the test piece was peeled off from the stainless steel plate in the direction of 180° at a rate of 30 cm/min, and the peel strength (gF/cm) was measured.

4) The average peel strength (gF/cm) was calculated from the integrated value of the measured peel strength in a section showing steady peeling. A high peel strength represents excellent tackiness.

(Evaluation of Adhesiveness of Patch)

In the following examples, the adhesiveness of a patch to the skin was evaluated by the following method. The patch was applied to the skin of the subject. After 24 hours, the degree of adherence of the patch was visually observed. The patch was rated as “A” when 90% or more of its area adhered to the skin, and as “B” when it was otherwise.

Test Example 1

Patches (placebo patches) having the compositions shown in Table 1 were prepared. In the table, “PET film”, “PET film/PET nonwoven fabric”, “PU film/PU nonwoven fabric” and “PET knitted fabric” refer to a film made of PET, a laminate of a film made of PET and a nonwoven fabric made of PET fibers, a laminate of a film of PU and a nonwoven fabric made of PU fibers, and a knitted fabric made of PET, respectively. The rubber adhesive in Table 1 is a mixture of an SIS block copolymer and PIB and comprises the SIS block copolymer and PIB in a mass ratio of 19:7. As “PET knitted fabric”, one having a water vapor transmission rate of 5667 g/m²·24 hours, a 50% modulus in the longitudinal direction of 3.9 N/50 mm and a 50% modulus in the transverse direction of 3.4 N/50 mm was used (the same applies to the following examples). The patch was placed in an incubator at 30° C. and 65% RH with a backing layer facing upward and a release film facing downward, and stored. After 24 hours, DMSO was extracted from the patch and quantified by GC. The storage conditions are conditions simulating the environment when the patch is worn on skin for 24 hours.

The results are shown in Table 1, FIG. 1 and FIG. 2. Compared to the patches of Reference Examples 1 and 2 each having a backing layer with the water vapor transmission rate of less than 400 g/m²·24 hours, decrease in DMSO concentration after storing for 24 hours was much greater with the patches of Reference Examples 3 and 4 each having a backing layer with the water vapor transmission rate of 400 g/m²·24 hours or more. There was observed such a relationship as the patch having a backing layer with a high water vapor transmission rate was high in the decrease rate of the DMSO concentration in the adhesive layer (FIG. 1) and short in the half-life of the DMSO concentration (FIG. 2).

The tackiness of each of patches stored under the same conditions for 24 hours was also evaluated. The results are shown in Table 1. The patches of Reference Examples 3 and 4 each having a backing layer with the water vapor transmission rate of 400 g/m²·24 hours or more were better in tackiness (peel strength) after stored for 24 hours, as compared with the patches of Reference Examples 1 and 2 each having a backing layer with the water vapor transmission rate of less than 400 g/m²·24 hours.

Furthermore, patches having the compositions shown in Table 1 were evaluated for the adhesiveness after 24 hours. The results are shown in Table 1. The patches of Reference Examples 3 and 4 each having a backing layer with the water vapor transmission rate of 400 g/m²·24 hours or more were good in adhesiveness after worn for 24 hours.

TABLE 1 Reference Reference Reference Reference Example 1 Example 2 Example 3 Example 4 Adhesive Rubber adhesive 31.3 31.3 31.6 31.7 layer (SIS/PIB = 19/7) Tackifier resin 44.6 44.6 44.9 45.1 Liquid paraffin 15.7 15.7 15.8 15.8 DMSO 3.4 3.4 2.7 2.4 Others 5 5 5 5 Total (% by mass) 100 100 100 100 Backing Material PET film PET film/ PU film/ PET knitted layer PET nonwoven PU nonwoven fabric fabric fabric Water vapor transmission rate 27 156 2077 5667 (g/m² · 24 h) Thickness (mm) — — 0.2 0.54 Basis weight (g/m²) — — 0.05 110 Results DMSO concentration after 24 hours 94 91 11 4.2 (vs. initial concentration %) DMSO concentration after 24 hours 3.20 3.10 0.30 0.10 (% by mass) Rate of decrease in DMSO 0.008 0.012 0.1 0.1 concentration (% by mass/h) Half-life of DMSO concentration (h) 274 180 7.6 5.2 Peel strength after 24 hours (gF/cm) 3.9 4.5 459 412 Adhesiveness after 24 hours of wear B B A A

Test Example 2

Patches having the compositions shown in Table 2 were prepared. The rubber adhesive in Table 2 is a mixture of an SIS block copolymer and PIB and comprises the SIS block copolymer and PIB in a mass ratio of 19:7. The tackiness of each of the patches of Examples 2 and 7 to 9 was evaluated by the probe tack value measured under the following conditions in accordance with the probe tack test method of ASTM D2979. A high prove tack value represents excellent tackiness.

Tester: Tacking tester (RHESCA Co., LTD.)

Material of the tip of probe part: stainless steel

Diameter of the adhesive face: 5 mm

Detaching rate: 2 mm/s

Adhesion load: 200 gF/cm²

Adhesion time: 1 second

In addition, one each of patches of Examples 1 to 15 and Comparative Examples 1 to 3 was applied to a healthy adult male on his lower back, and the adhesiveness after 24 hours was evaluated. The results are shown in Table 2. The patches of Examples 1 to 15 each having a backing layer with the water vapor transmission rate of 400 g/m²·24 hours or more were good in adhesiveness after worn for 24 hours.

In addition, a patch of Example 2 was placed in an incubator at 30° C. and 65% RH with a backing layer facing upward, and stored. After 24 hours, the DMSO concentration (% by mass) in the adhesive layer was quantified by GC and the change in the DMSO concentration was examined. The DMSO concentration after 24 hours was 1.2% by mass based on the total mass of the adhesive layer, which corresponds to 33% based on 100% of the initial (before storage) DMSO concentration. The decrease rate of the DMSO concentration and the half-life of the DMSO concentration calculated from the change in the DMSO concentration was 0.1% by mass/hour and 15 hours, respectively.

TABLE 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Adhesive Ketoprofen 5.0 2.0 layer Diclofenac sodium 5.0 2.0 Indomethacin 5.0 2.0 Rubber adhesive 35.1 32.8 35.1 35.1 32.8 35.1 Tackifier resin 34.8 32.4 34.8 34.8 32.4 34.8 Liquid paraffin 16.1 15.1 16.1 22.1 21.1 22.1 DMSO 2.0 7.7 2.0 2.0 7.7 2.0 Citric acid 2.0 2.0 2.0 1.0 1.0 1.0 Oleic acid 5.0 5.0 5.0 3.0 3.0 3.0 Mesylic acid 0 0 0 0 0 0 Total 100 100 100 100 100 100 Backing Material PET knitted PET knitted PET knitted PET knitted PET knitted PET knitted layer fabric fabric fabric fabric fabric fabric Water vapor transmission rate 5667 5667 5667 5667 5667 5667 (g/m² · 24 h) Results Probe tack value just before — 71.0 — — — — application (gF) Adhesiveness after 24 hours A A A A A A of wear Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Adhesive Ketoprofen layer Diclofenac sodium 5.0 5.0 5.0 5.0 5.0 5.0 Indomethacin Rubber adhesive 34.4 35.2 35.1 35.1 35.1 35.1 Tackifier resin 34.1 34.8 34.8 34.8 34.8 34.8 Liquid paraffin 15.8 16.2 16.1 16.1 16.1 16.1 DMSO 3.6 1.8 2.0 2.0 2.0 2.0 Citric acid 2.0 2.0 2.0 7.0 0 0 Oleic acid 5.0 5.0 5.0 0 7.0 0 Mesylic acid 0 0 0 0 0 7.0 Total 100 100 100 100 100 100 Backing Material PET knitted PET knitted PET knitted PET knitted PET knitted PET knitted layer fabric fabric fabric fabric fabric fabric Water vapor transmission rate 5667 5667 5667 5667 5667 5667 (g/m² · 24 h) Results Probe tack value just before 211 209 216 — — — application (gF) Adhesiveness after 24 hours A A A A A A of wear Comparative Comparative Comparative Example 13 Example 14 Example 15 Example 1 Example 2 Example 3 Adhesive Ketoprofen 7.0 2.0 layer Diclofenac sodium 7.0 2.0 Indomethacin 7.0 2.0 Rubber adhesive 35.1 32.8 35.1 35.1 32.8 35.1 Tackifier resin 34.8 32.4 34.8 34.8 32.4 34.8 Liquid paraffin 12.1 11.1 12.1 19.1 18.1 19.1 DMSO 2.0 7.7 2.0 2.0 7.7 2.0 Citric acid 2.0 2.0 2.0 2.0 2.0 2.0 Oleic acid 7.0 7.0 7.0 5.0 5.0 5.0 Mesylic acid 0 0 0 0 0 0 Total 100 100 100 100 100 100 Backing Material PU film/ PU film/ PU film/ PET film PET film PET film layer PU nonwoven PU nonwoven PU nonwoven fabric fabric fabric Water vapor transmission rate 2077 2077 2077 27 27 27 (g/m² · 24 h) Results Probe tack value just before — — — — — — application (gF) Adhesiveness after 24 hours A A A B B B of wear

Test Example 3

Patches having the compositions shown in Table 3 were prepared. For each of the patches having the compositions shown in Table 3, the probe tack value was measured in the same manner as in Example 2, and the tackiness was evaluated. The rubber adhesive in Table 3 is a mixture of an SIS block copolymer and PIB and comprises the SIS block copolymer and PIB in a mass ratio of 19:7. “Rubber/polyester fabric” in Table 3 refers to a polyester fabric coated with a rubber composition. The PU film (water vapor transmission rate: 786 g/m²·24 hours) in the patch of Example 16 and the PU film (water vapor transmission rate: 8408 g/m²·24 hours) in the patches of Examples 17, 19 and 20 are “3M CoTran 9701 Backing” and “3M CoTran 9700” from 3M Company, respectively.

Patches of Examples 16 to 19 and Comparative Examples 4 and 5 were evaluated for the adhesiveness after 24 hours. The results are shown in Table 3. In addition, the patches of these Examples and Comparative Examples were placed in an incubator at 30° C. and 65% RH with a backing layer facing upward, and stored. After 24 hours, the DMSO concentration (% by mass) in the adhesive layer was quantified by GC and the change in the DMSO concentration was examined. The results are shown in Table 3. The patches of Examples 16 to 19 each having a backing layer with the water vapor transmission rate of 400 g/m²·24 hours or more were good in adhesiveness after worn for 24 hours.

TABLE 3 Comparative Comparative Example 16 Example 17 Example 18 Example 4 Example 19 Example 5 Adhesive diclofenac sodium 5.0 5.0 5.0 5.0 5.0 5.0 layer Rubber adhesive 32.6 32.6 32.6 31.5 31.5 29.2 (SIS/PIB = 19/7) Tackifier resin 32.3 32.3 32.3 31.2 31.2 28.9 Liquid paraffin 15.0 15.0 15.0 14.5 14.5 13.4 DMSO 8.0 8.0 8.0 10.9 10.9 16.6 Citric acid 2.0 2.0 2.0 2.0 2.0 2.0 Oleic acid 5.0 5.0 5.0 5.0 5.0 5.0 Mesylic acid 0 0 0 0 0 0 Total (% by mass) 100 100 100 100 100 100 Backing Material PU film PU Rubber/ PET film PU PET film layer nonwoven polyester nonwoven fabric fabric fabric Water vapor transmission 786 8408 422 27 8408 27 rate (g/m² · 24 h) Results Probe tack value just before 53 68 44 41 61 29 applied (gF) Adhesiveness after 24 hours A A A B A B of wear DMSO concentration after 3 3 10 98 12 90 24 hours (vs. initial concentration %) DMSO concentration after 0.2 0.2 0.8 10.7 1.3 15.0 24 hours (% by mass) Rate of decrease in DMSO 0.325 0.325 0.300 0.008 0.400 0.067 concentration (% by mass/h) Half-life of DMSO 4 4 7 1049 8 163 concentration (h) 

1. A patch comprising: a backing layer; and an adhesive layer laminated on the backing layer, wherein a water vapor transmission rate of the backing layer is 400 g/m²·24 hours or more, and the adhesive layer comprises a drug, dimethylsulfoxide and an adhesive.
 2. The patch according to claim 1, wherein the water vapor transmission rate of the backing layer is 750 g/m²·24 hours or more.
 3. The patch according to claim 1, wherein the water vapor transmission rate of the backing layer is 2000 g/m²·24 hours or more.
 4. The patch according to claim 1, wherein the adhesive layer comprises at least one adhesive selected from a rubber adhesive, an acrylic adhesive and a silicone adhesive.
 5. The patch according to claim 1, wherein the adhesive layer comprises a styrene-isoprene-styrene block copolymer.
 6. The patch according to claim 1, wherein the drug is one or more drugs selected from the group consisting of ketoprofen, diclofenac sodium and indomethacin.
 7. The patch according to claim 6, wherein the adhesive layer comprises an organic acid.
 8. The patch according to claim 3, wherein the adhesive layer comprises a styrene-isoprene-styrene block copolymer.
 9. The patch according to claim 8, wherein the drug is one or more drugs selected from the group consisting of ketoprofen, diclofenac sodium and indomethacin.
 10. The patch according to claim 9, wherein the adhesive layer comprises an organic acid. 